Abstract: (Meth)-acrylic acid esters of the formula ##STR1## in which R.sup.1 and R.sup.2 are each independently hydrogen, chlorine, fluorine or a C.sub.1 - to C.sub.4 -alkyl radical andR.sup.3 and R.sup.4 are identical or different and represent the group ##STR2## wherein Y is a divalent bridge member from the group ##STR3## and Z is a straight-chain or branched hydrocarbon chain which has 2 to 10 carbon atoms, can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals,whereinR.sup.5 represents hydrogen or methyl andR.sup.6 represents hydrogen, C.sub.1 -C.sub.6 - alkyl or phenyl,which are useful as dental materials.

Abstract: The invention relates to novel (meth)-acrylic acid derivatives of tricyclodecanes of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and denote hydrogen, lower alkyl, lower alkoxy, halogen or trifluoromethyl and R.sup.3 and R.sup.4 are identical or different and represent the groups. ##STR2## in which X is a divalent bridge member comprising the group ##STR3## and Y is a linear or branched hydrocarbon chain which has 2 to 10 carbon atoms and can optionally contain oxygen bridges and is optionally substituted by 1 to 4 acrylate or methacrylate radicals, andR.sup.5 represent hydrogen or methyl andR.sup.6 represents hydrogen, lower alkyl or phenyland to their use in dental compositions.

Abstract: Improved electrostatographic suspension developers contain a pigment coated with polycyanoacrylate.Wherein the polycyanoacrylate comprises an inner shell on a pigment dispersed in an electrically insulating carrier liquid having a volume resistance of at least 10.sup.9 ohm.cm and a dielectric constant below 3 and the pigment has an additional shell of a copolymer ofA. cationic monomers which contain ammonium, phosphonium or sulfonium groups and of which the anions are derived from CH-acid compounds containing at least one C.sub.6 -C.sub.24 hydrocarbon radical andB. radically polymerizable olefinically unsaturated compounds as comonomers.

Abstract: The use of microporous inorganic fillers in polymerizable compositions, in particular in the dental field, characterized in that the fillers have(a) an average particle size of 0.5 to 50.mu.,(b) a BET-surface area of at least 200 m.sup.2 /g,(c) a pore volume of 0.7 to 5 ml/g and(d) a pore diameter of 10 to 50 nm.Fillings made therefrom are smooth and easy to polish.

Abstract: An electroviscous fluid comprising more than 25% by weight of silica gel with a water content of 1 to 15% by weight, a non-conductive oily phase dispersion medium, 1 to 30% by weight of one or more polymers soluble in the dispersion medium, the weight percentage being based on the water-containing silica gel, and the polymers having a molecular weight in the range of from 5.times.10.sup.3 to 10.sup.6 and containing 0.1 to 10% by weight of N and/or OH and 25 to 83% by weight of C.sub.4 to C.sub.24 -alkyl groups. Such electroviscous fluids are useful for transmitting powerful forces by means of a low electronic output, for example, in hydraulic valves and shock absorbers.

Abstract: (Meth)-acrylic acid esters of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and denote hydrogen, chlorine, fluorine or a C.sub.1 - to C.sub.4 -alkyl radical andR.sup.3 and R.sup.4 are identical or different and represent the group ##STR2## wherein R.sup.5 and R.sup.6 are identical or different and denote hydrogen or methyl,Z denotes a straight-chain or branched C.sub.2 - to C.sub.8 -alkylene chain andn denotes values from 1 to 4. Such (meth)-acrylic acid esters can be used as dental fillers or to coat teeth.

Abstract: An electrostatographic suspension developer contains a dispersed pigment and a copolymer ofA. cationic monomers which contain ammonium, phosphonium or sulfonium groups and of which the anions are derived from CH-acidic or sulfur- or phosphorus-containing acidic compounds containing at least one C.sub.6 -C.sub.24 hydrocarbon radical andB. radically polymerizable, olefinically unsaturated compounds as comonomersin an electrically insulating carrier liquid having a volume resistivity of at least 10.sup.9 ohm. cm and a dielectric constant below 3.

Abstract: An electrostatographic suspension developer contains, in an electrically insulating carrier liquid with a volume resistivity of at least 10.sup.9 Ohm. cm and a dielectric constant of below 3, a dispersed pigment and a polymer of basic secondary or tertiary amino group-containing monomers, the amino groups of which are completely or partially neutralized with a Bronsted acid, which contains at least one hydrocarbon radical having from 6 to 24 carbon atoms, and optionally further comonomers.

Abstract: A filler for a polymerizable composition comprising an inorganic core of particles with a particle size of 10 to 500 nm, a first shell of vinylsilane and a second shell of a (meth)acrylate polymer. The filler is then used to prepare dental moldings of acrylates in conventional manner. The moldings are very hard and abrasion resistant.

Abstract: The suspension developer contains, in an electrically-insulating carrier liquid, a pigment and a block copolymer comprising a block of polymerized vinylaromatic compounds and a block of polymerized dienes the double bonds of which have been partially or completely reacted with alkyl mercaptans. The developer is distinguished by its high dispersion stability, small particle size and uniform particle size distribution.

Abstract: A dental composition suitable for being polymerized to a dental prosthesis approximately comprising by weight(A) 20 to 50% of a mixture of monofunctional and polyfunctional methacrylic esters and, optionally, other monomers,(B) 20 to 60% of an essentially non-crosslinked polymer homogeneously filled with microfine inorganic filler and based on (meth)acrylic esters and, optionally, other monomers,(C) 0.5 to 25% of a non-crosslinked polymer having a glass transition temperature.ltoreq.0.degree. C. and a molecular weight M.sub.w of 10.sup.3 -5.times.10.sup.5, and(D) 0 to 40% of a finely divided inorganic filler treated with an adhesion promoter.

Abstract: The suspension developer contains as a toner polymer-sheathed pigment particles in an electrically insulating carrier liquid. The sheath of the pigment particles is formed by precipitation polymerization from various (meth)acrylates, a cross-linker and, optionally, a vinyl or vinylidene monomer. The developer has an outstanding dispersion stability which does not change during use or storage.

Abstract: In a photopolymerizable composition comprising(a) at least one ethylenically unsaturated photopolymerizable monomer.(b) at least one photoinitiator selected from organic mono- and/or di-carbonyl compounds and(c) a photoactivator, the improvement which comprises employing as said photoactivator at least one alkylaminoarylsulphonyl compound of the formula ##STR1## in which R.sub.1 and R.sub.2 each independently is a hydrogen atom or an alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl group which has 1 to 11 carbon atoms and is optionally substituted by at least one hydroxyl, amino, epoxy, urethane, urea, ether of ether group, or R.sub.1 and R.sub.2 together form a 3- to 6-membered ring, which optionally contains nitrogen, oxygen or sulphur as a hetero-atom,R.sub.3 independently of R.sub.1, has any of the meanings given for R.sub.1 or is a group of the formula ##STR2## R.sub.4 and R.sub.

Abstract: The invention provides dental materials in paste form consisting essentially of (a) 18 to 50% by weight of a polymerizable binder, (b) 20 to 65% by weight of a crosslinked bead polymer with an average particle size of 5 to 150 .mu.m and (c) 5 to 45% by weight of glass beads with an average particle size of 5 to 80 .mu.m. The pastes of the invention are outstandingly suitable as a dental filling material.

Abstract: Polymer beads having an average bead diameter of from 5 to 500 .mu., consisting of an inorganic fine-particled filler and polymerized (meth)acrylic acid esters, and a process for their production, wherein a mixture of monomer and, optionally, polymer which is soluble in the monomer, which has a viscosity of from 0.1 to 10 Pa.s, measured at the dispersion temperature, and filler is suspended in an aqueous medium in the presence of dispersants and is polymerized.

Abstract: A process for the polymerization of methyl methacrylate or mixtures thereof with up to 25%, by weight, based on total monomer, of vinyl monomers copolymerizable therewith, wherein polymerization is carried out in the presence of from 0.01 to 10%, by weight, based on total monomer, of one or more enol ethers derived from aliphatic or cycloaliphatic aldehydes or ketones.

Abstract: The invention includes dental materials based on organic plastics in paste form, comprising at least one phase consisting essentially of finely divided, crosslinked plastics which contain copolymerized ester(s) of methacrylic acid to the extent of at least 50% by weight, and the second phase consisting essentially of ester(s) of methacrylic acid to the extent of at least 50% by weight. The materials can be used for making prostheses, crowns, bridges, artificial teeth, dental fillings, etc.

Abstract: A dental material is provided based on organic plastics in paste form, which consists essentially of (a) a polymerizable binder, (b) a crosslinked bead polymer and (c) a fine-particled inorganic filler.

Abstract: The invention provides dental materials which are opaque to X-rays and are based on organic plastics in paste form, which comprises (a) a polymerizable binder, (b) a crosslinked bead polymer and (c) an X-ray contrast medium. The materials can also contain as an additional component (d) a fine-particled inorganic filler which is not opaque to X-rays. The materials are useful, inter alia, for filing dental cavities.

Abstract: Bead polymers having a mean bead diameter of from 10 to 200.mu. of one or more polymerized viscous methacrylates and/or dimethacrylates having a viscosity of from 0.5 to 500 Pa.s and, optionally, up to 20% by weight of one or more other vinyl monomers.